Air circulating apparatus



Sept. 1, 1953 P. l.. SCHNEIDER AIR CIRCULATING APPARATUS Filed Dec. l, 1949 Patented Sept. 1, a 1953 AIR CIRCULATING APPARATUS Paul L. Schneider, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware .Application December 1, 1949, Serial No. 130,462

l This invention relates to heating and ventilating systems for motor cars which provide for the circulation of air in the passenger compartment either by the use of a power driven blower or by air taken in from the front of the car.

One of the chief criticisms of the heating and Ventilating systems for motor cars which take outside air from the front of the car is the introduction of air considerably contaminated by exhaust gases from other vehicles into the car. This condition is most serious when the car is being driven at relatively low speeds, or is standing, where congested trafc conditions exist.

One of the advantagesof taking the air for the heating and Ventilating system from the front of the car is that the use of a power driven .blower is not required when the car is being driven at moderate speeds or faster. However, the use of the power driven blower is required to force enough outside air into the car to keep the windows from fogging when the car is being driven at low speeds or is standing. Consequently, the blower could be arranged to take air from a region of relatively low contamination and thus reduce the hazard involved when driving in congested traffic.

An object of this invention is to take advantage of the entrance of air into the heating and ventilating system of the `car by impact pressure when the car is driven at higher speeds and to provide for a shift in the place of entrance of the air when the blower is required, so that the entrance of badly contaminated air into the car is avoided.

In the embodiment of the invention the air pipe leading to the interior of the body is connected by valve either with a duct leading from the front of the vehicle or with the outlet of a blower, said valve being moved automatically to block the outlet of the blower when air pressure in the duct is sufticient, or to block the duct in response to the operation of the blower which is eifected automatically when air pressure in the duct is insufficient.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a diagram of the embodiment of the invention, the air pressure controlled switch controlling the blower motor circuit being shown in sections.

Fig. 2 is a sectional view on line 2-2 of Fig. 1, with certain parts omitted.

2 Claims.

Referring to Fig. 1, IIJ represents a casing having air inlets Il and an outlet I2. The casing encloses a blower which is driven by an electric motor I3 connected with a current source terminal I 4 by the ignition switch I5 and by an automatic switch 30. The current source may be a storage battery I6, or the generator (not shown) which charges the battery. The pipe 20, which leads to the air circulating system of the automobile body, is connected either with the blower outlet I2 or with an air inlet duct 21| which is connected with a louvre opening at the front end of the automobile. The air supplied to the outlet I2 enters the inlets II which are positioned in a region around the car where the air is of relative low contamination by exhaust gas of adjacent vehicles, for example the inlets may be in a region under the hood of the car or in the right fender of the car. The connection of pipe 2t either with blower outlet I2 or duct 2| is controlled by a valve 22 attached to a shaft 23 pivotally supported by a Wall 24 which separates the blower outlet I2 and the duct 2|. As shown in Fig. l, the valve 22 is in position blocking duct 2l and opening blower outlet I2. Valve 22 is retained in this position by a spring 25 attached to a stud 2S supported by partition 24 and to a lever 2l attached to shaft 23 on the exterior of the housing Il. The spring is so arranged with respect to the post 26 and the lever 21 that the line of spring force passes through the pivot point bar of the shaft 23. Thus the spring will impart snap motion to the valve 22 when the line of spring force is moved to either side of a deadcenter position. When the ignition switch l5 is closed, the blower motor I3 begins to run, forcing air into the car body through duct 20. This produces a certain amount of air pressure in this duct which assists the spring 25 in holding valve 22 in position, blocking duct 2l. As the vehicle speed increases, pressure in duct 2l in direction of arrow 28 and in the pipe 6I increases until it reaches a value suflicient to eiect the opening of the normally closed switch in unit 3B. The motor I3 will then be disconnected from the current source, and the blower will stop. Air pressure in duct 2|] then drops, allowing the air pressure in duct 2| to move valve 22 against spring 25 so the valve moves to position 22. When this change occurs, pressure in duct 20 is suucient for proper circulation of air into the vehicle body without the use of the blower.

When car speed falls below a value, such that the air pressure in duct 2l is insufficient to maintain proper circulation of air through pipe 20 to .case x32.

.is connected with lever-V33 'and the other .nested by a spring E with a noncondue 'clamp the parts 252-55 vagainst va shoulder o :flange :5.8 .of la` cover itil, .said iiangeV 5i? around `at 15.9 vagainst zthe flange .provides together'with A.the diaphragm the car body, the switch in the unit 30 will be permitted to close automatically to effect connection of motor I3 with the current source and the blower I will operate and the pressure of air in the blower outlet l2 will be suiiicient to 5 cause the valve 22 to return from position 22 to the position blocking duct 2| and fully opening outlet f2.

The switch unit V3i) comprises a contact 3l normally engaging a contact 32. Contact 3i is carried by a lever 33 pivoted on a pin 3ft mounted in suitable openings in a pair of spaced depending arms 35a of a bracket 35. The "bracket '35 is electrically connected with ia bracket brackets B and 36 beinginsulated ironia 15 31. The brackets 35 and 35 are attached to the base 31 by rivets 15. The rivets are suitably insulated from the brackets '355 and Contact 32 supported by a bracket 3S is electricallg7 cennected with a bracket E139, said brackets 3B and echoing-supported by :the base insulated therefrom and from thebracketsleii The base 'S1-supports.-aplateftt having l reinsulated from lthe cover t2 and .respectively lfor connection with with switch i5-and motor i3. RinPf provid .a sealto prevent entrance of 'dirt into ,contact 32 by aU-springii, one branch ci U-shaped .lever et which 'straddles the ar The iarm's .have-suitable openings to "nocive .pin '.34 aso that it is `also pivotally supported by Lever d@ Yhas `an extension 41 conver..

the pin 34.

clip '49 attached -to'bracket 39. Spring 48 urges lever i5 zcounterclockwise vinto engagen'ient wi a rnon-conducting .tlrlm'ble '5t attached to o. rod .5l passing'through the base 31 and through a washer .52, a .hanged disc 1.53, ya diaphragm 'and la washer "5.5. The rod Vis riveted over to rod 51|. lT-he :periphery of .diaphragm o: -1 clampedbetweenlthe'flange 1.5i of 31 th seing bei Cover :pressure'chambericonnected witharpipe J extends*withinlthe'duct 2i and which is ben., to

face toward the air {cui-rent indicated by '2;3. Normally the spring t5 is in such positron with respect to its 4connection with levers and 55 --Ii-S'that its plane will vbeloc-ated below the axis of Vlever-33 to move counterclockwise until it strikes a stop 62 attachedto base 31 and insulated therefrom. Thereforecontact 3l separates from contact i752 and the current source is disconnected 7 from `the motor 3 and the blower it stops.

The-sWitch-unit 3@ is supported by a bracket 'iii 4 to which the base 31 is attached by studs 13 arranged to pass through holes in the bracket and receiving nuts 12 and lock washers 1l. lThe vent 31a in base 31 for the diaphragm chamber connects with a passage 3113 formed by a groove 31e located next to bracket 10 when base 3,1 is attached thereto. This arrangement prevents dirt Ypassing freely @through `the vvent into Tthe diaphragm chamber. The l.vent `.31a sorestricts the flow of air out from or into the diaphragm chamber as the diaphragm moves that surging of the switching action is minimized.

While the embodiment of the present invention ras herein disclosedpconstitutes a preferred form,

it is to be understood that other forms might be adopted.

What is claimed is as follows:

l. An air circulating apparatus comprising a v.pipe connected with a compartment; a pair of ducts connected at junction with the pipe; a blower Vconnected ^to `one -voi? thejducts -Y and the other duct ofsaidfducts being subjected to ow oi air in response to yforward movement'of said duct; a valve pivotally `mounted at the junction of the ducts, said 'valve normally closing the first duct and operable to openthe rst=duct and close the second duct; a `lever connected to vthe valve; an 'over-center tension'springvhaving its ends connected :respectively vto saidl lever `vand a stationary part whereby-said lever can be moved to snap Athe 'valve yfrom one `position fto another position; switch .means :supported y-exteriorly `of the ducts andpipe to control :the-blower; `andra diaphragm Ycontrol device operatively connected in said other duct by ymeans of a Pitot tube having one end positioned with said otherduct Jfor actuating theswitch means'to Vopen position when air iow pressure in said other duct reaches a predetermined position to render the blower inoperative.

2. An vair irculating apparatus comprising 'a pipe connected with 'a compartment;Y 'a yfpair @of ducts connected at junction with the gpipe; :a

Vblower connected to one yof the ducts and the other duct of .said ducts .being subjected vto :ow of air in response to forward" movement .of said duct; Ya valve pivotally Vmounted at "the l.junction of the ducts, said valve norrnallyr closing :the rst duct and operable to openthe frst duct andlclose the second duct; la Alever connected to the-valve;

. an over-center tension springha'ving :its ends connected respectively `to vsaid Vlever Vand :a stationary part whereby said lever `can be moved vto snap the valve from one Vposition vto another position; switch means supported yexteriorlyyof the ducts and pipe to control the blower; Vdiaphragm controldevice externally located of :said ductsand pipe andfhaving anoperating member disposed in said other duct for .actuating vthe Vswitch means to open position Vwhen'air pressure in said other duct reaches a certain value to render blower inoperative.

PAUL L. SCHNEIDER.

References cues in the 'sieV Vof rms'patet U NIIED STATES .PATENTS Number Name '-Date 1,990,753 Rapp -Feb 12, k1935 2,032,572 Hammers et al. an Mar '3, 1936 2,251967 Le `Febreet-al. Oct. '7, '1941 

